Question

Why is $CHC{l_3}$ polar even though the electronegativity difference is smaller than $1.0$ ?

Answer 1

Chemical elements are the purest form of atoms. Atoms combine to form molecules. Chloroform is a molecule with the atoms of carbon, chlorine and hydrogen. There is a small electronegativity difference between these atoms, but this molecule is a polar molecule due to the asymmetrical distribution of bonds resulting in dipole moment leads to non-por molecule.

Complete answer:
Chloroform is a compound with the molecular formula of $CHC{l_3}$ it consists of one carbon, one hydrogen and three chlorine atoms. The chloroform molecule exists in the $s{p_3}$ hybridization and exhibits a tetrahedral geometry.
The bonds involved in chloroform are $3C - Cl$ and $1C - H$ bonds. Though, there is not much difference in the value of electronegativity between these atoms it can have a polar nature and can be considered as a polar compound.
As the four bonds involved in chloroform are not symmetrical, due to the difference in electronegativities, the $1C - H$ bond will be differently arranged and the geometry of the tetrahedron will be slightly distorted. Thus, there is an electron displacement and net dipole moment will arise in this molecule that leads to the polar character.
Due to the dipole moment of chloroform, it can be considered as a polar.

Note:
The electronegativity difference between the carbon, chlorine and hydrogen is not greater than $1$ . Thus, it should be a covalent character, but it is a polar due to the dipole moment. Hence, not only the electronegativity difference, the net dipole moment, and geometry must be considered while writing the nonpolar or polar character.